One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(5,6)(7,11)(8,10)(9,12) involution — undirected(5,7)(6,9)(8,12)(10,11)(14,18)(15,22)(16,19)(20,27)(21,25)(23,26) involution — undirected(2,4)(7,12)(9,11)(13,14,19,25,17,21,16,18)(15,20,26,28,23,27,22,24)(6,10)(9,11)(15,23)(20,27)(22,26)(24,28) involution — undirected(13,15,19,26,17,23,16,22)(14,20,25,28,21,27,18,24)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.